Watercraft steering mechanism and trimmer

ABSTRACT

The invention concerns a steering and trimming system for a watercraft ( 1 ) whereby control is exercised via the steering wheel ( 2 ) at low speed by means of crossbeam rudders ( 13,14 ) and when planing via a rudder ( 29 ). In addition, during the craft&#39;s acceleration phase, the trim arms ( 22 ) are more quickly brought into position.

TECHNICAL AREAS OF APPLICATION

The invention involves control of watercraft by means of steering and trimming equipment in accordance with the preamble of the initial claim.

TECHNICAL STATUS

For thousands of years the preferred method of steering vessels has been achieved by means of rudders which may consist of one or several surfaces and, since the arrival of the small outboard motors and drives as described in patent DE 1 025 293, certain watercraft are directly controlled by the propeller. More recently, various refined systems have come to light particularly for faster craft using e.g trim wedge steering known as Humphree systems or differential deflectors as described in Patent WO 03/093102.

Trim arms are used to improve the planing angle on watercraft, to correct poor weight distribution, to displace the buoyancy areas using flow deflectors in order to bring a vessel more quickly into the planing position as described in U.S. Pat. No. 3,628,487.

DESCRIPTION OF THE INVENTION

The invention is based on the requirement for a simplified but effective method of steering, which is efficient even under the influence of wind and current, as well as an automatically and rapidly acting trimming operation for the vessel from start to planing by means of trim arms which can be used in conjunction with the steering system.

The difficulty when progressing slowly as happens in a harbor is that the steering rudder surfaces—due to poor flow on the rudder profiles—react poorly, and the drive units of Z drives or surface propeller equipment have extremely limited maneuverability, so that for the purposes of invention under a pre-determined speed the system is automatically switched over to the more efficient control characteristics of a cross beam rudder where the thrust is dependent upon the position of the steering wheel and on switching over to reverse the direction of the thrust of the cross beam rudder is turned so that for a given steering wheel position the craft is automatically correctly steered in the reverse direction. A further improvement to the steering is the utilization of a variable pitch propeller on dual equipment which can set the pitch of the propeller in forward thrust and the other propeller in reverse thrust, where the difference in pitch of both propellers to each other is dependent upon the position of the steering wheel, as well as upon the vessel's speed data.

The invention is considered to have achieved this by way of the features set out in the initial claim.

The main aim of the invention is to guarantee optimal steering at any speed without rudders or expensive propeller mechanism and at the same time to reduce as much as possible steering mechanism resistance in the water at greater speeds as well as improving reversing operations of craft in harbors and facilitating automatic trimming in fast gear during the vessel's acceleration phase.

Further advantageous features of the invention can be derived from the sub-claims

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the drawings the following explains in greater detail the features of the invention. Similar components in the various drawings have the same reference code.

The drawings are described as follows:

FIG. 1 A schematic view of a vessel with the most important steering and reversing elements with respect to sensors and electronics as well as fluid control on the variable pitch propeller and steering arms.

FIG. 2 A schematic view of a vessel with the most important steering and reversing elements, namely thrust direction indicator and propeller thrust indicated by a single blade when planing and steering the vessel to the left.

FIG. 3 A schematic view of the vessel with the most important steering and reversing elements, namely thrust direction indicators and propeller thrust shown by a single blade during harbor maneuvers and steering the vessel to the left and forwards.

FIG. 3 a A schematic view of a vessel with the most important steering and reversing elements, namely thrust direction indicator and propeller thrust shown by a single blade during harbor maneuvers and steering the vessel to the left and astern.

FIG. 4 A schematic view of a vessel with the most important steering and reversing elements with respect to sensors and electronics as well as hydraulic control for the bow and stern beam rudder.

FIG. 5 A schematic view of a vessel with the most important steering and reversing elements, namely propeller thrust direction indicator as well as the thrust direction indicator of the cross beam rudder at low speed in forward and steering the vessel to the left.

FIG. 5 a A schematic view of a vessel with the most important steering and reversing elements namely, propeller thrust direction indicator as well as the thrust direction indicator of the cross beam rudder at low speed when steering astern and to the left.

FIG. 6 A schematic view of a vessel with the most important steering and reversing elements, namely the propeller thrust direction indicator as well as the thrust direction indicator of two cross beam rudders at low speed in forward motion and steering the vessel to left.

FIG. 6 a A schematic view of a vessel with the most important steering and reversing elements, namely the propeller thrust direction indicator as well as the thrust direction indicator of two cross beam rudders at low speed astern and steering the vessel to the left.

FIG. 6 b A schematic view of a vessel in a 180° turn in two positions with the most important steering and reversing elements, namely the propeller thrust direction indicator as well as the thrust direction indicator of two cross beam rudders at low speed and steering to the left as well as when traveling forwards F and astern R.

FIG. 7 A schematic view of a vessel with the most important steering and reversing elements, namely the propeller thrust direction indicator as well as a thrust direction indicator for a steering arm and its resistance in water at planing speed and while steering the vessel to the left.

FIG. 8 An isometric projection of a steering arm with a curved flow deflector and guide rails to lower the steering arm into the water flow behind the vessel as well as a sketch of a bracket to secure an activating device.

FIG. 9 A schematic side view section through a steering arm, which can also be used as a trim arm with two independent activators to control the steering or trimming operations.

FIG. 10 A schematic cross section through a steering arm in the steering operation position which at the same time can be used as a vessel trimming arm.

FIG. 11 A schematic cross sectional view through a steering arm in the trimming position which at the same time can be used as a vessel trimming arm

Only essential elements of the invention are shown to facilitate immediate understanding.

METHOD OF DESIGN USED FOR THE INVENTION

FIG. 1 Shows a schematic view of a watercraft 1 with a steering wheel 2 fitted to a steering column which via a path measuring unit 3—which can be an angle measuring device, a eccentric lift sensor or a positional switch—delivers data 3 a to a controller 4 which passes on a signal 4 a from the hydraulic unit 5 in order to open the appropriate directional control valve 6 and via the hydraulic line 5 a for the variable pitch propeller or the hydraulic line 5 b for the steering arm to execute the required movement by means of an activator 7 and a steering activator 16. The activator 7 and the steering activator 16 have a path measuring device, which sends the data back to the controller to carry out an actual against nominal value comparison. The hydraulic unit 5 and the directional control valve 6 work as long as the nominal value is achieved. Thus, the activator 7 can control a variable pitch propeller 8 to displace its blade 9, the steering activator 16 and the steering arm 10. Furthermore, the steering depends upon the speed component 11 of the craft 1 which is relayed to the controller 4 via the speed component 11 a.

The measurable speed of a watercraft 1 can be processed by the controller 4 e.g. the engine revs as a measured quantity, by the motor revs×blade pitch of the propeller 8, by using the GPS system or by using the back pressure reading on the vessel and the like.

At a defined speed e.g. harbor speed and because of a defined logic other activators 7 can be operated at high speed. Furthermore, control of activator 7 also depends upon the position of the reversing lever 12 whereby this has a path measuring device and the measured value signal 3 c which gives the position of the reverse lever 12. To what extent neutral N, forward position F, astern position R or the completely shut down system NO was selected is also taken into account by the controller.

It is understood that steering displacement does not only refer to the hydraulic unit 5 but a pneumatic version is also possible with the proviso that only lockable activators may be used which lock the selected position over middle so that compressibility of the compressed air due to pressure fluctuations can have no effect on the position of the propeller blade 9 or the steering arms 10.

In addition, steering displacement can be effected electrically—the activator 7 being an electric motor.

With dual motor systems the controller 4 also has the task of synchronizing the speed components 11 of both motors, whereby the path measuring unit 3 of the reverse lever is also included as a measured quantity. Where necessary the reverse lever 12 can be coupled to the accelerator to form a single unit.

FIG. 2 Shows a schematic view of a watercraft 1 with a steering wheel 2 and a steering angle to the left (to port) and the reverse lever 12 in the forward position F. The steering angles determined via the path measuring unit are passed on to the controller 4. At the same time the controller 4 records the speed component 11 of the vessel 1 and the position of the reverse lever 12, whereby in this case an exemplary planing speed was recorded. This permits the controller 4 to select the planing mode program and via the hydraulic system 5 to operate the activator 7 to enable the left side propeller 8 to reduce its blade inclination. This ensures that on the port side of the vessel there is a slowing down effect of the thrust of the right propeller and this then permits the vessel 1 to turn to the left. The arrows show the thrust differential of both propellers 8. At high speeds the propeller blades 9 do not turn in the negative areas and as such do not produce any backward thrust.

It is also feasible that the right side propeller can produce more thrust, whereby care should always be taken to ensure that the controller 4 maintains both motor revs at a constant value so that when moving in an arc there are no troublesome changes of motor speed.

FIG. 3 Shows a schematic view of a vessel 1 with a steering wheel 2 turning to the left with the reverse lever 12 in the forward position F. The steering angle and the control is identical to that shown in FIG. 2, whereby in this case the controller 4, due to the reduced speed component 11, has selected the slow ahead program—as is the practice in harbor maneuvers—and in doing so with a full turn for example to the left, the left propeller 8 is turned to a maximum reverse thrust position so that a negative thrust of propeller 8 can be produced, which has more turning effect than just one small but positive blade pitch at the left propeller 8. The arrows illustrate the thrust forces PS. As long as the propeller thrust PS of the right propeller 8 is greater than those of the left propeller, the craft 1 will turn left.

FIG. 3 a Shows a schematic view of a vessel 1, with a steering wheel 2 turning to the left and the reversing lever 12 in the reverse position R. The steering angle is identical to that shown in FIG. 3, whereby in this case when going from forwards F to backwards R the blades 9 are turned back to front, so that the propeller thrust PS of the right propeller 8 is shown in a negative reverse direction, the left propeller 8 having less thrust is shown in the backwards direction or even as indicated completely in the forwards direction, so that the vessel 1 travels backwards and when viewed in the direction of travel turns to the right like a car with the same steering movement having the same effect.

A slight movement of the steering wheel 2 leads to minimal pitch differential of the propeller blade 9 as opposed to propeller 8. Each increase in steering wheel angle leads to an increase of the pitch difference of propeller 8.

If craft 1 does not undertake any movement forwards F or backwards R then in the neutral position N the vessel can be turned on its axis. For this the propeller blades 9 are brought into a counter rotating pitch so that the thrust forces of both propellers 8 are identical, but acting in the opposite direction.

FIG. 4 Shows a schematic view of a craft 1 with a steering wheel 2 mounted on a steering column, which via a path measuring device—which for example can be an angle measuring device, an eccentric lift sensor or a positional switch—relays the measured value 3 a to a controller 4 which relays the signal 4 a to the hydraulic system 5 for the purposes of opening the directional control valves 6 which could preferable be proportional valves. Via the hydraulic piping 5 c the hydraulic motors are activated to drive the bow cross beam rudder 13 and the stern cross beam rudders 14, 15. It is advantageous that with increased steering angle on the steering wheel 2 the revolutions of the hydraulic motor 15 are increased, so that the thrust of the cross beam rudders 13, 14 is increased accordingly. If the cross beam rudders 13, 14 are equipped with variable pitch blades then the steering angle of the steering wheel can have a direct influence on the blade pitch of the cross beam rudders 13, 14.

Furthermore the controller 4 checks the speed component 11, since both cross beam rudders 14,15 are activated only below a certain speed. The position of the reverse lever 12 is a further input factor and is similarly taken into account by the controller 4, where the reverse lever has a path measuring system 3 and the signal 3 c, which gives the position of the reverse lever as to whether it is in neutral N, forward position F or stern position R.

It is to be understood that the crossbeam rudder drive 15 does not only involve the hydraulic unit 5 but that it can be either pneumatically controlled or driven by an electric motor.

FIG. 5 Shows a schematic view of a watercraft 1 with a steering wheel 2 and steering angle to the left and the reverse lever 12 in the forwards position F. The steering angle determined via the path measuring device 3 is transmitted to the controller 4. At the same time the controller 4 records the speed component of the craft and the position of the reverse lever 12. In this case the reduced speed—which is the practice in harbors—is recognized due to the low speed component 11 and thus using a full turn of the wheel for example to the left the hydraulic motor 15 of the stern beam rudder 14 is activated. The effect of this is that a crossbeam rudder thrust, indicated by arrow QS, is directed to the right and the craft as a result turns to the left.

The greater the steering wheel angle to the steering wheel 2 the greater will be the crossbeam rudder thrust QS of the stern beam rudder 14.

FIG. 5 a Shows a schematic view of a watercraft 1 with a steering wheel 2 and a steering angle to the left and the reverse lever in the stern position R. The steering angle is identical to FIG. 5 whereby in this case when reversing from forwards F to stern R the crossbeam thrust of the stern beam rudder 14 is activated in the opposite direction, as shown by the arrow QS, so that the craft 1 seen in the direction of travel as shown by arrow PS turns right as happens when steering a vehicle, having the same effect.

FIG. 6 Shows a schematic view of a watercraft 1 with a steering wheel 2 turning to the left and with the reverse lever in the forwards positions F. The steering input is identical to that shown in FIG. 5 whereby in this case an additional bow beam rudder is activated whose crossbeam thrust shown by the arrow QS is opposite to the crossbeam thrust of the stern beam rudder 14. A steering angle for example to the left produces a crossbeam thrust QS at the stern cross rudder to the right, at the same time it produces a crossbeam thrust at the bow beam rudder 13 to the left. The greater the steering wheel angle to the steering wheel the greater the crossbeam thrust of both crossbeam rudders 13, 14.

FIG. 6 a Shows a schematic view of a watercraft 1, with a steering wheel 2 and steering angle to the left and the reverse lever in the stern position R. The steering angle is identical to that shown in FIG. 5 whereby in this case the crossbeam thrust of the bow beam rudder 13 and the stern beam rudder 14 are in opposite directions, so that the craft 1 looking in the direction of travel and indicated by the arrow PS turns to the right as when steering a vehicle, having the same effect.

If a craft 1 does not undertake a movement forwards F or backwards R then the craft can be turned on its axis in the neutral position N since in this position there is no propeller thrust PS but the steering wheel lock still activates the crossbeam rudders 13, 14.

Moving the reverse lever 12 to NO (not pictured) disengages all steering and control activities. The propeller is also mechanically disengaged, although in the neutral position it continues to turn without producing any thrust.

FIG. 6 b Shows a schematic view of a watercraft in a 180° turn with radius Ra in the travel condition as described in FIGS. 6 and 6 a. The steering angle is constant, only in forwards F is the thrust of the bow cross beam rudder activated to the left, in the reverse direction R the thrust of the bow crossbeam rudder 13 is activated to the right and the stern beam rudder reacts in the opposite direction so that the craft 1 can be driven in a circle forwards and backwards without altering the steering wheel angle.

FIG. 7 Shows a schematic view of a watercraft 1, with a steering wheel 2 turning to the left and the reversing lever in the forward position. The steering angle derived from the path measuring system 3 is relayed to the controller 4. At the same time the controller 4 records the speed component 11 of craft 1 and the position of reverse lever 12, whereby in this case the planing speed was recorded. This permits the controller 4 to select the planing mode and gives instruction to the hydraulic system 5, as described in FIGS. 1 and 2, and in this case to the steering activator 16 which operates the steering arm so that it is lowered into the water. The effect of this is that the water flow WS is directed to the steering arm 10 and produces a side thrust SS on the left side of the craft 1 whereby resistance occurs which causes the craft 1 to turn to the left.

The greater the steering wheel angle to the steering wheel 2, the deeper the steering arm lowers into the water, the greater the side thrust SS and the greater the resistance RR.

The programs reduced speed or planing mode and the associated activation of the crossbeam rudder 13, 14 or of the steering arm 10 do not need to be fixed, but can be fluid. Switching off one or the other steering modes whereby the steering activator 16 or hydraulic motor 15 are not permanently activated together is highly desirable because of the energy saved which can be used to increase the pressure of the hydraulic system 5.

The combination of the crossbeam rudders 13, 14 with a steering arm 10 or a composite arm 21 is feasible. Even a normal rudder, which at slow speeds produces very little control pressure, can benefit from an automatic reversal of the crossbeam rudders 13, 14.

FIG. 8 Shows an isometric view of a steering arm 10 with a curved flow deflector 17, whereby any shape and skewing of the flow deflector 17 is permitted, which exerts an influence on the lateral side thrust. A cover 18 connects the flow deflector with the guide rails 19 to lower the steering arm 10 into the water flow and serves to secure the bracket 20 for the steering activator 16 and also serves as a spray water deflector. Of course, the bracket 20 may also be directly fitted to the guide rails 19.

FIG. 9 Shows a schematic side section through a composite steering arm 21 which at the same time can be used as a steering arm 10 and a trim arm 22, with two independent activators each being equipped with a path measuring device, a steering activator 16 and a trimming activator 23 to trim craft 1. The design of the steering arm 10 includes a bottom lip 24 so that the water flow WS is channeled and the lateral transverse thrust SS is also increased. In extreme cases the channel K can consist of a curved pipe in order to deflect the water flow accordingly.

The composite arm 21 is held by means of a longitudinal guide 25 and is fixed to the arm frame 26. The arm frame 26 is secured to the craft 1. By means of a pivot bearing the steering arm 10 or the trim arm can be lowered individually or both together.

The steering arm is lowered by turning the steering wheel 2, the greater the turn the deeper the steering arm lowers into the water. The trim arm is automatically lowered in the start phase, fine adjustment of the trim arm 22 is carried out manually by an activator (not shown) on the steering column of craft 1.

FIG. 10 Shows a schematic side cross section through a composite arm 21 in the steering position in accordance with FIG. 9. The water flow WS is lead into channel K and at the same time the water resistance RR is increased by the introduction into the water of the steering arm 10 on one side, which makes the craft turn.

FIG. 11 Shows a schematic side cross section of a composite arm 21 in accordance with FIG. 9 in the trim operation position. The water flow WS is activated by lowering the trim arm 22 which produces an upward force LK on craft 1. It is also feasible that the steering activator 16 can be lowered by the thickness of the bottom lip which leads to resistance similar to trim wedge steering, which similarly releases an upward force on craft 1; the trim activator 23 is lowered at the same time.

The controller 4 which, using the speed component 11 calculates the craft's speed as well as the reverse lever 12 which can be coupled with the motor accelerator (not shown) and the attached path measuring device 3, can be used for automatic trim arm control, .e. the speed determines how quickly the reversing lever 12 together with the accelerator is pushed forward—this leads to a signal—a measured value over time—which is relayed to the hydraulic system 5, the directional control valve 6 and the hydraulic accumulator 28, so that the trimming activator 23 is activated and the trim arm 22 is instantly lowered. The involvement of the hydraulic accumulator 28 ensures that there is sufficient pressure available to supply the trim arm with oil as quickly as possible. When the craft 1 picks up speed the trim arm 22 is continually returned to its starting position. The effect of this is that when the craft 1 is started the bow of the craft 1 does not lift excessively due to fact that the trim arm 22 extends immediately. As soon as the craft 1 reaches planing speed the trim arm is retracted whereby the reaction process can occur continually. The trim arm setting in this operation occurs simultaneously and in parallel.

Of course the invention is not limited to the example so depicted and described. 

1. Control for a watercraft with at least one engine and one steering device is characterized by the fact that direction control is achieved at slow speed by the steering wheel by means of the crossbeam rudders and at greater speed automatically by means of rudders, or for a twin motor craft using pitch changes of propellers, or when reversing with instantaneous steering lock at low speed, the direction of thrust of the crossbeam rudders or the pitch of the blades of propeller is turned as a mirror image.
 2. Control in accordance with claim 1 wherein the steering angle of steering wheel determines the number of turns of the crossbeam rudders and as such the transverse thrust of the crossbeam rudders
 3. Control in accordance with claim 2 wherein with a turn of the steering wheel and the associated activation of the bow cross rudder and of a rear cross rudder, the direction of thrust of both crossbeam rudders is in the opposite direction.
 4. Control in accordance with claim 1 wherein above a predetermined speed the crossbeam rudder is disengaged electronically.
 5. Control in accordance with claim 1 wherein, with twin motors, the steering angle of steering wheel and the positioning of the blade of one variable pitch propeller relative to the other leads to a pitch difference between the two propellers.
 6. Control in accordance with claim 5 wherein, upon turning the steering wheel to port, that port side variable pitch propeller reduces its pitch and when turning to starboard, the starboard side variable pitch propeller reduces its pitch.
 7. Control in accordance with claim 5 wherein the revs of both motors are electronically controlled so that the revs of both motors remain constant when the steering wheel is turned and the blade is consequently displaced.
 8. Control in accordance with claim 1 wherein the position of the propeller blade with both motors is dependent upon the speed component, the position of the reverse lever and the steering angle position of the craft's steering wheel.
 9. Control in accordance with claim 1 wherein when the steering lock of steering wheel is to port, that port side steering arm is lowered down and when the steering lock is put to starboard the starboard side steering arm is lowered.
 10. Control in accordance with claim 9 wherein the steering arm is angled towards the craft producing a lateral thrust.
 11. Control in accordance with claim 9 wherein that steering arm is located at the stern and bottom of the craft.
 12. Control in accordance with claim 9 wherein the section of the steering arm, acting as a flow deflector, has the profile of a partial or full pipe.
 13. Control in accordance with claim 9 wherein the steering arm can be disengaged electronically below a defined speed.
 14. Control in accordance with claim 9 wherein the composite arm forms a common flow body consisting of the steering arm and the trim arm together with two independent activating cylinders.
 15. Control in accordance with claim 14 wherein the composite arm also has an arm frames, a longitudinal guide and a pivot bearing.
 16. Control in accordance with claim 1 wherein the rudder can be a steering arm, a composite arm, a vertical rudder or a trim wedge plate.
 17. Control in accordance with claim 1 wherein the steering wheel shaft is attached to a path measuring device which sends a measured value 3 a as well as values 3 b and 3 c to the controller for a nominal/actual comparison and this is corrected to the nominal value by the hydraulic system.
 18. Control in accordance with claim 8 wherein the speed component of the vessel is measured using an engine rev factor or engine revs×propeller pitch or GPS and is passed on to the controller.
 19. Control in accordance with claim 1 wherein the path measuring devices are fitted to the reverse lever, the activator and the steering activator.
 20. Control in accordance with claim 14 wherein when the vessel accelerates, the trim arms are quickly and automatically pointed downwards and at a predetermined speed, the trim arms are raised so that the vessel, when planing, takes up an optimal planing angle.
 21. Control in accordance with claim 8 wherein information on how quickly the motor accelerator is operated, the direction of the reverse lever and the speed components is available in the controller when the trim arm is automatically lowered.
 22. Control in accordance with claim 20 wherein the hydraulic system has a hydraulic accumulator to assist the trim activator when moving the trim arm.
 23. Control in accordance with claim 20 wherein a second element for the trim activator operates at twice the speed of a standard unit.
 24. Control in accordance with claim 14 wherein at least one of the activator cylinders is mechanically locked and the lock is activated automatically as soon as the desired height is reached. 